TiC, W₂C Reinforced Ti-W MMC Coating Developed on Ti-6Al-4V Substrate Through Laser Cladding

High specific strength, corrosion resistance and subzero to moderately elevated working temperature are the intrinsic properties of Ti-6Al-4V, which turn it one of the favourite aerospace engineering materials. Relatively soft and poor wear resistive properties restrict its further essential applications. In the present work, attempts were carried out to improve tribological properties of Ti-6Al-4V surface by developing hard and bulk clad layers for longer service life of that product. A pre-placed powder mixture of tungsten, graphite and titanium over the substrate, was irradiated by a fibre laser in argon shroud. The laser clad layers developed with in situ TiC and W₂C reinforced in Ti-W matrix that were confirmed by HR XRD phase analysis. Effects of laser scan speeds on coatings formation, microstructure, microhardness, and dry sliding wear performance were investigated. The microhardness of the coated surfaces was improved up to 700 HV_0.05 on an average whereas microhardness value of the untreated Ti-6Al-4V substrate was 350 HV_0.05. The dry sliding wear performances of the hard coatings significantly improved.